Antibacterial Activity of Low-Density Polyethylene and Low-Density Polyethylene-co-maleic Anhydride Films Incorporated with ZnO Nanoparticles

• Published in: Food and bioprocess technology 2021-10, Vol.14 (10), p.1872-1884
• Main Authors: de Souza, Roberta Cristina, de Moraes, Jaqueline Oliveira, Haberbeck, Leticia Ungaretti, de Araújo, Pedro Henrique Hermes, Ribeiro, Deise Helena Baggio, Carciofi, Bruno Augusto Mattar
• Format: Article
• Language: English
• Subjects: Agriculture; Antibacterial activity; Biotechnology; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Density; Food packaging; Food safety; Food Science; Fruit juices; Low density polyethylenes; Maleic anhydride; Nanoparticles; Original Research; Physical properties; Polyethylene; Polymer films; Polymers; Pseudomonas aeruginosa; Salmonella; Shelf life; Zinc oxide; Zinc oxides
• ISSN: 1935-5130; 1935-5149
• DOI: 10.1007/s11947-021-02684-1

This study innovatively produced polymeric active antibacterial films by incorporating zinc oxide nanoparticles (ZnO-NP) into linear low-density polyethylene grafted with maleic anhydride (LLDPE-MA) and low-density polyethylene (LDPE) using polymer melting and coating of ZnO-NP. It was evaluated the physical properties and antibacterial effects against foodborne pathogens ( Staphylococcus aureus , Salmonella  Typhimurium, and Pseudomonas aeruginosa ) by liquid and disk-diffusion in agar tests. The active films presented 1.0, 2.5, and 5.5% of ZnO-NP. The two with higher ZnO-NP content presented similar antibacterial activity, demonstrating that the ZnO-NP availability on the film surface is more important than their total amount. Disk-diffusion in agar showed an inhibition halo for P. aeruginosa in both films with more than 5.0% in ZnO-NP, whereas for S. aureus and S.  Typhimurium, the inhibition zones were not detected after 48 h. In liquid tests, P. aeruginosa was the least sensitive microorganism: from 5 log CFU/mL, it reached 9 log CFU/mL in LLDPE-MA films without ZnO-NPs and 7 log CFU/mL in films with 5.5% of ZnO-NPs after 5 days. S . Typhimurium was the most sensitive in the liquid test, with 9 log CFU/mL growth in 5 days for films without ZnO-NPs and 3 log CFU/mL for 5.5% of ZnO-NPs, in 5 days. In conclusion, ZnO-NP incorporated on LLDPE-MA and LDPE films is a promising packaging technology to increase food shelf-life and safety.